Coated paper and process of manufacture



April 30, 1935. .1. E. SCHOPP COATED PAPER AND PROCESS OF MANUFACTUREFiled June 27, 1952 IN N TO K Jam E 056% A TTORNE V Patented Apr. 30,1935 I UNETED STATES PATENT OFFICE COATED PAPER AND PROCESS OFMANUFACTURE John E. Schopp, Oak Park, Ill.

Application June 27, 1932, Serial No. 619,375

8 Claims. (01. 91-68) The objects of this invention are: one hundredparts by weight of clay or other pig- First, to provide varnished paperlabels or any ment, fifty-three parts by weight of water and varnishedpaper that is of a superior quality and approximately seven parts byweight of dry casein. can be manufactured very economically, and a Afterthis coating is applied in the conventional process for making the same.manner I partially dry the paper and then apply Second, to provide acoated paper suitable for a two pound coating containing about fiveparts varnishing and the process of making the same. by weight of drycasein to one hundred parts by Third, to provide such a paper that isimperweight of water. The paper is then dried and vlous to varnish andwhich will not change color after printing a coat of varnish is appliedin any 10 when varnished. usual manner, such as by the use of a machine10 Fourth, to provide such a paper that will not as illustrated in Fig.l-A or by what is known absorb ink or varnish that is applied thereto.as overlay varnishing, which is merely printing Objects pertaining todetails and economies of the varnish on the sheet with the usualprinting my invention will definitely appear from the deprocess.scription to follow. The invention is defined in Paper coated in thisway is a superior product 15 the clalms. for varnishing and is in muchdemand. The var- The manner of carrying out my invention is nish is heldup by the coating because of the layer clearly illustrated in theaccompanying drawing. of adhesive applied after the original coating, inwhich: which makes the final coated paper practically Fig. 1 showsdiagrammatically apparatus for impervious to varnish.

carrying out my new process and manufacturing I am aware of the wellknown process of applymy new product. ing two like coatings to a sheetand know that Fig. l-A shows diagrammatically apparatus such processesdo not embody the advantages of for varnishing sheets of my improvedpaper. my process or produce my product. Fig. 2 shows diagrammatically adifferent type Referring to the drawing, my process in detail 25 ofapparatus for applying coating. is as follows:

Fig. 3 shows diagrammatically a still different I is a roll of paperwhich is preferably a hardp of apparatus for pp y Coatingssized paper,which I have found gives better re- Hel'etofole, in Order t0 make a P pa e sults, although a soft-sized or unsized paper can 0 for varnishing,it has been necessary to use large b t t d by my rocess, 2 is a coatingapplying quantities of casein or other adhesive and to use machinecomprising a color pan 3 and brass rolls a in white which is m re expnsiv than cl y l and 5 through which the web 5 of paper passes. f r hcoating in order to m k a p p r f h The lower roll 5 picks up thepigment from the class pr y my p To make a p p color pan and applies itto the face of the paper that is the closest to my paper but which is1111- web 6, and the roll 4 is so positioned that it presses 35satisfactory the P 'D necessary to use the paper and regulates theamount of coating as a C atin about O hundred pa by Weight applied tothe paper. The device is conventional of satin Whi e to tw ywtwenty-five parts and is illustrated only diagrammatically. y weig t ofCasein- The usual Clay sized P The paper web 6 then passes over endlessrubin which Seve pa s y Weight of Casein and her apron 1 running overrolls 8 where oscillating 40 One hundred parts y Weight O Clay are usedis brushes 9 spread out the coating. The paper is 1101? a a yy means ofy process I a fed along by means of perforated rubber blanket succeededin making a better sheet more economiin having a suction means therein.The means Cally by pp yin tw separate in difi' ing illustrated are allconventional and are illustrated from one another in their nature.diagrammatically. 45

In describing my invention I refer to a fifteen In carrying out myprocess, in color pan 3 I pound coat. This is the usual paperterminology place a coating composition made up of one hunand indicatesthat the coating applied to the paper dred parts by weight of clay,fifty-three parts by is of such weight that the coating applied to aweight of water and fifty parts by weight of casein ream of fivehundreds sheets of I paper twentysolution. Fifty parts of caseinsolution is equal five by thirty-eight inches weighs fifteen pounds. toabout seven parts dry casein, and the solution Those skilled in the artwill understand this terherein referred to is made up of one hundredminology without further explanation. parts by weight of casein, sixhundred parts by In my process I first coat the web of paper with weightof water and five parts by weight of soda a fifteen pound coatingcontaining approximately ash.

natural calcium sulphate, or any other pigment that may be used in thecoating of paper. Instead of casein it is possible to use any adhesiveused in coating paper or suitable for such use, such as starch or glue,and I do not wish to be limited to the use of casein alone, although itis the best adhesive now available. It is also possible to use anysuitable alkali instead of soda ash in making the casein solution. Thevarious pigments can be blended as desired and the adhesives can also beblended to obtain desired results.

After the paper has passed the suction apron ill it is festooned oversticks II for drying. At this point in carrying out my process, I drythe paper until it is partially dry. I prefer to leave about fifteen totwenty per cent of moisture in the paper, but this can be varied. I haveillustrated the drying as .-by festooning the paper, which'is well knownin the trade. It may also be dried by steam coils or blasts of heatedair may be blown upon the paper, the only requisite being that the paperbe dried.

The paper passes from the drying to a serie of wooden rolls I2 which areconventional and smooth out any wrinkles in the web.

The web passes then to a second coating applying apparatus I3 similar inall respects to the apparatus 2. The coating is then treated as beforeby oscillating brushes M and the web is fed along by suction apron l5similar to suction apron Ill. The paper is then festooned on sticks l6and dried, as is well known in the art, and passes over a metal guide I!through smoothing rolls I8 where it is wound on storage roll I9.

In the apparatus I3 I apply a coating difierent from that applied in themachine 2. I apply a two pound coating. To apply this coating I use asolution comprising thirty-five parts by weight of casein solution suchas heretofore described, or about five parts by weight of dry casein toone hundred parts by weight of water in the apparatus I3. The coating isapplied as before and the steps of treatment above outlined arefollowed. Instead of casein, any desired adhesive, as stated above, canbe used, and it is not necessary to use casein in the apparatus 2 andalso in the apparatus 13. Any desired adhesive may be used in eitherapparatus without departing from my invention.

The proportions of materials may be varied but they need never be raisedto the quantities required by the former treatment. In manufacturing myproduct, I have referred to applying a fifteen pound coating to thepaper and then applying a two pound coating of the adhesive. Myinvention can be used in varying proportions, and I have found that thesecond coating, to-wit, the adhesive, can be as light as or lighter thanone pound. The proportions by weight of the pigment for the firstcoating may vary considerably from the ratio heretofore described. Thesefactors are dependent upon the sizing of the paper to be coated and itsabsorptive qualities.

I have described the production of a seventeen pound coating. Forheavier coatings a heavier coat is put on the paper in the firstinstance and the second coating may be as described or of a differentweight, depending upon the conditions. The first coating is usually onethat will stick to the paper but is not a coating that in and of itselfwould be sufiicient, although I have found that a much better sheet ofpaper can be made if a coating that was heretofore consideredsatisfactory is given a light second coat of adhesive.

The paper produced is coated by a bound coating of the clay with a thinoverlaid film of the adhesive alone, which makes the paper impervious tovarnish or ink.

In Fig. 2 I illustrate an apparatus 20 for use in place of either theapparatus 2 or l3. This apparatus has a color pan 2|, brass roller 22,brush 23 for applying the coating to the web 6 as it is carried around abras roll 24. I

In Fig. 3 is an apparatus 25 that can be used in place of apparatus 2 orapparatus 13, or apparatus 20. A color tank 26 is provided with brassrolls 2'! and 28 through which the web 6 of paper passes. Nozzle 29discharges the coating on the sheet and the rolls 2? and 28 squeeze itto regulate the quantity applied.

In Fig. l-A I show apparatus suitable for applying varnish to my paper.The varnish can be applied immediately after the paper is completed.This is not done if the paper is to be printed for labels because avarnished sheet will not take ink and the printing would not beprotected by the varnish. The apparatus shown is for use in applyingspirit varnish to printed labels or other sheets.

The sheets 30 are fed between rubber roll 3| and brass roll 32. Therubber roll 3| applies varnish taken up by brass roll 33 from tank 34.The labels 3!) are then fed to a continuous conveyor 35 which passesbeneath suitable drying means 36, here illustrated as a hood withsuitable inlets 31 for heated air. The labels are fed through the dryingapparatus and are stacked as shown at 38. The varnish used is a copalgum and denatured alcohol solution. Other varnishes may be applied andthe varnish may be applied by printing, which is known as overlayvarnish.

The paper produced in this manner may be produced for wall paper as wellas labels and is suitable for any use wherein a waterproof paper isdesired.

Modifications of my process can be utilized for making a. paper that isvery resistant to ink and the quantities of materials used may belowered considerably and the paper thus treated will, although notsuitable for varnish, be suitable for printing and be a superiorproduct.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. The method of making varnished paper comprising coating the paperwith a mixture of pigment and casein in which the quantity of casein issuflicient to hold the pigment to the paper during manipulation of thepaper in coating but is not sufiicient to permanently hold the pigmentto the paper, drying said coating, applying a second coating of fromapproximately 1 to approximately 2 pounds in weight comprising caseinonly, drying said second coating and applying a coat of varnish.

2. The method of making paper for printing comprising coating the paperwith a mixture of pigment and casein in which the quantity of casein issufiicient to hold the pigment to the paper during manipulation of thepaper in coating but is not suflicient to permanently hold the pigmentto the paper, drying said coating and applying a second coating of fromapproximately 1 to approximately 2 pounds in weight comprising caseinonly.

3. The method of making paper for printing comprising coating the paperwith a mixture of pigment and an adhesive selected from the classconsisting of glue, starch and casein, in which the quantity of saidadhesive is sufficient to hold the pigment to the paper duringmanipulation of the paper in coating but is not suflicient topermanently hold the pigment to the paper, drying said coating, applyinga second coating of from approximately 1 to approximately 2 pounds inweight comprising said adhesive only.

4. The method of making paper for printing comprising coating paper witha coating having therein approximately parts by weight of pigment to 7parts by weight of casein, drying said coating and then applying theretoa coating of casein of from approximately 1 to approximately 2 pounds inweight.

5. An article of manufacture comprising a sheet of paper made by coatingthe paper with a mixture of pigment and casein in which the quantity ofcasein is suflicient to hold the pigment to the paper duringmanipulation of the paper in coating but is not suflicient topermanently hold the pigment to the paper, drying said coating, applyinga second coating of from approximately 1 to approximately 2 pounds inweight, comprising casein only, drying said second coating and applyinga coat of varnish.

6. An article of manufacture comprising a sheet of paper made by coatingthe paper with a mixture of pigment and casein in which the quantity ofcasein is sufiicient to hold the pigment to the paper duringmanipulation of the paper in coating but is not sufiicient topermanently hold the pigment to the paper, drying said coating andapplying a second coating of from approximately 1 to approximately 2pounds in weight comprising casein only.

'7. An article of manufacture comprising a sheet of paper made bycoating the paper with a mixture of pigment and an adhesive selectedfrom the class consisting of glue, starch and casein, in which thequantity of said adhesive is sufiicient to hold the pigment to the paperduring manipulation of the paper in coating but is not suflicient topermanently hold the pigment to the paper, drying said coating, applyinga second coating of from approximately 1 to approximately 2 pounds inweight comprising said adhesive only.

8. An article of manufacture comprising a sheet of paper made by coatingpaper with a coating having therein approximately 100 parts by weight ofpigment to '7 parts by weight of casein, drying said coating and thenapplying thereto a coating of casein of from approximately 1 toapproximately 2 pounds in weight.

JOHN E. SCHOPP.

